Atomizing device

ABSTRACT

An atomizer for atomizing liquids including a liquid storage receptacle pertaining to an atomizing device having an atomizing chamber that communicates with the ambient atmosphere through a plurality of outlet orifices. A vibrator is also provided, which liquid present in the atomizing chamber is caused to vibrate for the purpose of atomization, and an intake channel is provided, via which the liquid storage receptacle is connected to the atomizing device and a pumping device is also provided in the intake channel for the purpose of conveying the liquid from the liquid storage receptacle to the atomizing chamber, An electronic control device controls the pumping device and the vibrator.

FIELD OF APPLICATION AND PRIOR ART

This application claims the priority of the German patent applicationNo. 10 2010 024 913.0. The whole disclosure of this prior application isherewith incorporated by reference into this application.

The invention relates to an atomizer for atomizing liquids, moreparticularly pharmaceutical or cosmetic liquids. A generic atomizercomprises a liquid storage receptacle and an atomizing device comprisingan atomizing chamber that communicates with the ambient atmosphere bymeans of a plurality of outlet orifices, and a vibrator, by means ofwhich liquid present in the atomizing chamber can be caused to vibratefor the purpose of atomization. Furthermore, a generic atomizercomprises an intake channel, by means of which the liquid storagereceptacle is connected to the atomizing device, and a pumping devicethat is provided in the intake channel for the purpose of conveyingliquid from the liquid storage receptacle to the atomizing chamber. Anelectronic control device is provided for controlling the pumping deviceand the vibrator.

Generic atomizers are known in the prior art. They are used foratomizing liquids to a fine spray. These liquids are, in particular,pharmaceutical or cosmetic liquids. In the case of pharmaceuticalliquids, the purpose of atomization can consist, for example, in theproduction of a very readily inhalable spray by means of the atomizer.In the case of cosmetic liquids, the purpose of atomization can consistin achieving a very homogeneous discharge by means of the atomizer, forexample for the production of a very homogeneous layer of liquid on anarea of the skin.

The pumping device of generic atomizers can serve the purpose ofproviding a continuous supply of liquid to the atomizing device.However, it has been found that it is difficult to coordinate thepumping device and the atomizing device in such a way that the pumpedvolumetric flow rate produced by the pumping device perfectly matchesthe rate of atomization of the liquid. In the case of an extremely highpumped volumetric flow rate, there is the risk of deterioration of theatomizing characteristics in that the liquid flows through the dischargeorifices in a non-atomized state and covers the side of the dischargeorifices remote from the atomizing device with a liquid film to obstructatomization. In the case of an extremely low pumped volumetric flowrate, it is likewise impossible to achieve good quality atomization,since comparatively large amounts of air gather in the atomizationchamber and counteract the discharge of liquid in an atomized form.These disadvantages are particularly problematic in an atomizer that isintended for use in different positions. This positional variability canbe desirable for various reasons. Thus, for example, in an atomizer usedfor the inhalation of medicines, it is desirable that the atomizer beusable by the patient in different positions, for example, in a standingor lying position. In the case of an atomizer used for cosmetic productsthat are to be applied to different areas of the skin, it is difficultto do this when the atomizer is held in a constantly invariableposition. The variable orientation of a generic atomizer intensifies theaforementioned problem since it can promote the entry of air into theatomizing chamber. In addition, pressure conditions in the atomizingchamber depend to a major extent on the orientation and movement of theatomizer.

In order to deal with the problem of achieving coordination between thepumping device and the atomizing device, it is known in the prior art,for example from DE 10 2004 006 452 A1, to activate the pumping deviceand the vibrator successively. Initially, the atomizing chamber itselfand any capillary channel directly connected thereto are filled withliquid by means of the pumping device. Then the vibrator is activated inorder to discharge the amount of liquid introduced into the atomizingchamber and the capillary channel. The disadvantage of such a design isthat the amount of liquid discharged is small. It is thus impossible toachieve a continuous atomizing process. This is a considerabledisadvantage in the case of some medicines and also in the case ofcosmetic liquids.

OBJECT AND ITS ACHIEVEMENT

It is an object of the invention to develop a generic atomizer byachieving a continuous atomizing process whilst avoiding considerableeffort in achieving coordination between the pumping device and theatomizing device. More particularly, it is desired to provide anatomizer that is suitable for use in an atomizing process in which itcan be held at different orientations.

According to the invention, this object is achieved by the provision ofa return channel, which is distinct from the intake channel and servesto drain liquid from the atomizing chamber into the liquid storagereceptacle. Thus a channel leading from the atomizing chamber to theliquid storage receptacle is provided in such a design in addition tothe intake channel through which the liquid is conveyed by the pumpingdevice from the liquid storage receptacle to the atomizing chamber ofthe atomizing device. It is the primary task of this return channel torecirculate excess liquid from the atomizing chamber to the liquidstorage receptacle. This allows the atomizing chamber to be fed at avolumetric flow rate of liquid that is significantly greater than thedischarged volumetric flow rate as can be atomized by means of theatomizing device. The excess amount of liquid is not discharged throughthe outlet orifices, but instead it flows through the return channelback into the liquid storage receptacle. The return channel can bedimensioned appropriately for this purpose. This structure ensurescontinuous atomization of liquid, during which sufficient liquid isalways available for the purpose of atomization in that a volumetricflow rate of liquid that is clearly greater than the atomized volumetricflow rate is fed continuously to the atomizing chamber. Furthermore,even if air enters the atomizing chamber through the outlet orifices,the return channel enables this air to be removed from the atomizingchamber and to flow together with the excess liquid into the liquidstorage receptacle. Thus the atomizer of the invention ensures a veryreproducible and constant atomizing process.

The atomizing device of an atomizer of the invention is similar toatomizing devices known in the prior art. The liquid present in theatomizing chamber is caused to vibrate by the vibrator, which ispreferably in the form of a piezoelectric vibrator, such that areproducible discharge of liquid through the plurality of very smalloutlet orifices is achieved under substantially constant pressureconditions in the atomizing chamber. The liquid discharged is replaced,by means of the pumping device, with liquid from the liquid storagereceptacle. For this purpose, the pumping device is preferably in theform of a micropump. Such a micropump can have, for example, a pumpchamber which is provided with an inlet valve and an outlet valve andwhich is cyclically enlarged and reduced in volume by means of one ormore piezoelectric actuators.

For the purpose of achieving a homogeneous discharging behavior, thepumped volumetric flow rate of the liquid fed by the pumping device tothe atomizing chamber is greater than the discharged volumetric flowrate of liquid passing through the outlet orifices. The dischargedvolumetric flow rate depends significantly on the design of theatomizing device and on the activation of the vibrator by means of thecontrol device. The pumped volumetric flow rate depends on the design ofthe pumping device itself and its activation by the control device andthe design of the channels conveying the liquid. The desired pumpedvolumetric flow rate that is greater than the discharged volumetric flowrate can be achieved by means of an appropriate design of the atomizingdevice, the pumping device, and the channels, and particularly by meansof the activation thereof by the control device.

It is of particular advantage when the pumped volumetric flow rate isgreater than the discharged volumetric flow rate by at least 20% duringthe atomizing process. It is more advantageous when the pumpedvolumetric flow rate is greater than the discharged volumetric flow rateto an even greater extent. It is even more advantageous when the pumpedvolumetric flow rate is greater than the discharged volumetric flow rateby 40% or more. The homogeneity of the atomizing process is ensured veryeffectively when the amount of liquid delivered by the pumping device issignificantly greater than the amount of liquid atomized by theatomizing device.

In principle, it is feasible for the control device to be configured soas to start the pumping device and the vibrator simultaneously inresponse to a start signal, for example in response to actuation by auser. However, it is regarded as being advantageous when the controldevice is configured so as to activate the pumping device first in apreparatory phase before the atomizing process commences and toadditionally activate the vibrator on termination of the preparatoryphase. The preparatory phase, which preferably lasts at least 0.3seconds and more preferably at least 0.8 seconds, ensures that theatomizing chamber is completely filled with liquid prior to activationof the vibrator and that a positive pressure ensues in the atomizingchamber due to the activity of the device. These are ideal set-upconditions for subsequent activation of the vibrator and thus fortriggering the atomizing process.

Particularly to prevent liquid from being discharged through the outletorifices of the atomizing device under the pressure generated by thepumping device during the preparatory phase, it is advantageous for thepumping device to be configured and/or to be activated by the controldevice and for the outlet orifices of the atomizing device to beconfigured such that the pressure ensuing in the atomizing chamber inthe preparatory phase is not sufficient to force the liquid through theoutlet orifices. This can be achieved by the use of small outletorifices, by selecting a suitable shape of the outlet orifices, and/orby establishing a low pressure in the atomizing chamber. The pressuremust be adjusted such that it suffices only in combination with thevibrations produced by the vibrator to force the liquid through theoutlet orifices. A comparatively low pressure can be produced in theatomizing chamber by means of appropriate adjustment of the pumpingdevice. However, a throttle that is distinct from the pumping device isadvantageous for this purpose.

Basically any form of liquid reservoir can be used as the liquid storagereceptacle. In the simplest case, the liquid storage receptacle can be,for example, a dimensionally stable liquid reservoir, into which a riserpipe connected to the pumping device extends. Particularly with regardto the functional efficiency of the atomizer in various orientations, itis considered to be advantageous when the liquid storage receptacle isin the form of a dimensionally flexible liquid-containing bladder thatcan adapt itself in terms of its internal volume to the amount of liquidpresent therein. Such a dimensionally flexible liquid-containing bladderdoes not require any aeration since, irrespective of the remainingvolume, the pressure of the liquid in the liquid-containing bladder doesnot vary significantly, but instead is always equal to the ambientpressure. Such a liquid storage receptacle is filled exclusively withliquid except for the gaseous residues mentioned below, so that thepumping device will always draw in liquid. In the case of the presentinvention, the liquid storage receptacle has two openings, one of whichis connected to the intake channel and the other to the return channel.The use of a liquid-containing bladder is additionally advantageous dueto the very low risk of contamination associated therewith.

It is advantageous to provide a debubbling device since, inter alia,even the use of such a liquid-containing bladder cannot completelyexclude the possibility of gas entering the liquid-containing bladderwhen the latter is being filled with liquid and the further possibilityof air that has passed through the outlet orifices into the atomizingchamber of likewise entering the liquid storage receptacle by way of thereturn channel. The debubbling device is preferably provided in theintake channel and more preferably between the pumping device and theatomizing chamber.

This debubbling device ensures that the liquid fed to the atomizingchamber is free from gas bubbles, at least to a significant extent.Positioning of the debubbling device between the pumping device and theatomizing chamber additionally assists the removal of gas bubbles fromthe liquid in the debubbling device due to the pressure produced on thepump output side. Preferably, the debubbling device comprises a duct,through which the liquid flows on its way to the atomizing chamber andwhich is delimited, in part, by a filter surface. This filter surfaceallows the gas to escape at the pressure produced by the pumping device,while the pressure on the output side of the pump is not sufficient toforce the liquid through the filter surface. Preferably, the filtersurface is hydrophobic, in order to reduce contact with the liquid asfar as possible, so that any gas bubbles will be adsorbed on the filtersurface.

In a particularly advantageous design of the debubbling device, theaforementioned duct is formed by a groove that is located in a basecomponent and is closed by the flat porous filter surface applied tothis base component. This is a structurally very simple solution. Thebase component can be preferably provided in the form of a plasticscomponent, in which the groove is formed during manufacture of thecomponent, through which groove the liquid will flow on its way to theatomizing chamber. On its open side, this groove is closed by the porousfilter surface that can be of flat design for this purpose and cantherefore be produced very cost-effectively. The base component and thefilter surface, which is preferably in the form of a membrane, can bejoined together by gluing or welding.

It is regarded as being particularly advantageous when theaforementioned duct of the debubbling device comprises at least onecurved or bent portion. Here, it is important that the porous filtersurface be provided along this portion also. It has been found that sucha curved portion promotes the escape of gas through the porous filtersurface, presumably because most of the gas bubbles gather in the regionof the inside bend of the curves and are conveyed at a reduced speed inthis region. Preferably, several curved or bent portions are providedthat are variably oriented relatively to each other so that the removalof the gas bubbles is possible at different orientations of theatomizer. Furthermore, the duct including curved portions thatpreferably interconnect linear portions produces a long path of flow forthe liquid even in the case of a comparatively small component, so thatgas bubbles can leave the intake channel through the porous filtersurface over a comparatively long period of time.

As mentioned above, it is particularly advantageous when the liquidpresent in the liquid storage receptacle contains an activepharmaceutical ingredient and/or is a cosmetic product, moreparticularly a self-tanning lotion.

An atomizer of the invention can comprise flow meters both in the intakechannel and in the return channel, in order to make it possible toprecisely determine the amount of liquid that is atomized during adischarge process by taking the difference.

The atomizer of the invention is preferably in the form of a mobiledevice. For this purpose, it preferably comprises a battery or anaccumulator. In one particular embodiment, the device comprises auser-exchangeable pack of consumables not requiring special tools andincluding at least the liquid-containing bladder. This pack ofconsumables can additionally include the battery. The comparativelyexpensive components such as the electronic control device, the pumpingdevice, the debubbling device, and the atomizing device and optionallythe accumulator can be components of a base unit, to which the outerpack of consumables can be coupled.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional aspects and advantages of the invention are revealed in theclaims and the following description of a preferred exemplary embodimentof the invention, which is explained with reference to the figures, inwhich:

FIG. 1 is an overall view of an atomizer of the invention,

FIG. 2 shows the atomizer shown in FIG. 1 after removal of a housingshell,

FIG. 3 is a partially exploded view of the atomizer shown in FIGS. 1 and2, and

FIG. 4 shows the atomizing device of the atomizer shown in FIGS. 1 to 3.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

FIG. 1 is an overall view of an hand-held atomizer 10 of the invention.The atomizer 10 comprises a housing 12 that is approximately of the sizeof a cellular phone and that comprises two housing shells 14, 16. Arecess 14 a, behind which there is disposed an atomizing device 20(explained in more detail below), is provided in the top housing shell14. Furthermore, a control switch 18, by means of which the atomizer 10can be activated, is provided at the front of the atomizer formed by thehousing shell 14.

FIGS. 2 and 3 show the atomizer 10 in an open state, that is, afterremoval of the top housing shell 14. FIG. 3 shows some components in aposition removed from the housing 12 to make it possible to identify allsignificant components.

Two distinct regions 12 a, 12 b are provided inside the housing 12. Theregion 12 a contains a liquid storage receptacle 30 in the form of aliquid-containing bladder 30. Two openings (hidden in the figures), oneach of which a coupling device 32, 34 is provided for connection to aflexible tube, are provided on the liquid-containing bladder 30.

The aforementioned control switch 18 and the aforementioned atomizingdevice 20 are disposed in the region 12 b of the housing 12,Furthermore, a control device 40 and an accumulator (not shown) as anenergy storage device are provided in this region. The region 12 badditionally includes a piezoelectric pumping device 50 and a debubblingdevice 60.

The liquid-containing bladder 30 is connected to the atomizing device 20in the following manner. The coupling device 32 is connected to theinput side 50 a of the pumping device 50 by means of a flexible tube 70.An additional flexible tube 72 connected to an inlet 60 a of thedebubbling device 60 is provided on the output side 50 b of the pumpingdevice 50. This inlet 60 a adjoins a debubbling channel 66 that has beenformed as a groove in a base component 62 of the debubbling device 60.As shown in FIG. 2, the base component 62 is closed in a liquid-tightmanner in the assembled state of the atomizer 10 by means of a membrane64, more particularly an acrylic copolymer-based membrane that has ahydrophobic top coating and that can be glued or welded to the basecomponent 62 in the marginal regions of the groove. This membrane 64 isin the form of a porous membrane and serves the purpose of allowing gasbubbles to escape from the liquid flowing through the channel 66. At theopposite end of the channel 66, there is provided a throttle in the formof a bottle-neck region 68, the cross-sectional area of which issubstantially smaller than that of the channel portion 66 upstreamthereof. This bottle-neck region 68 adjoins an outlet orifice 60 b ofthe debubbling device 60. The atomizing device 20 (shown on an enlargedscale in FIG. 4) is provided directly at this outlet 60 b of thedebubbling device 60, and through-holes 64 a are provided in themembrane 64 to make this direct connection possible.

The atomizing device 20 comprises an atomizing chamber 22 locatedbetween a liquid inlet 20 a and a liquid outlet 20 b. On its side nearthe opening 14 a of the top housing shell 14, this atomizing chamber 22is delimited by a perforated plate 24 comprising a plurality of outletorifices 24 a. On its side remote from the perforated plate 24, theatomizing chamber 22 is provided with a wall 26, to which apiezoelectric vibrator 28 is attached, which is connected to the controldevice 40 by means of a cable (shown as a detail). Through-holes areprovided in the base component 62 and in the membrane 64 foraccommodating and wiring the piezoelectric vibrator 28.

The liquid outlet 20 b is provided for the excess liquid flowing fromthe atomizing chamber 22. In the assembled state of the atomizer, thisliquid outlet 20 b communicates with the inlet 80 a of a liquid channel80 that passes through the base component 62 of the debubbling device 60up to its outlet 80 b without a debubbling function being assigned tothis channel portion 80. A flexible tube 82 leading to theaforementioned second coupling device 34 of the liquid-containingbladder 30 is connected to the outlet 80 b.

Thus the liquid-containing bladder 30 is connected to the atomizingdevice 20 by means of the channel portions 70, 72, 66. This is theintake channel. The return channel is formed by the channel portions 80and 82.

The operation of the atomizer 10 is explained below.

For the purpose of discharging liquid from the liquid storage receptacle30, the user activates the control switch 18. This activation of thecontrol switch is registered by the electronic control device 40. Inorder to effect preparatory measures for a subsequent atomizing process,the electronic control device 40 activates the piezoelectricallyoperated micropump 50, initially alone. As a result, liquid is drawn infrom the liquid storage receptacle 30 through the flexible tube 70 andis further transported through the flexible tube 72 to the debubblingdevice 60. Here, the liquid flows into the channel portion 66. Due tothe pumping pressure built up at the output 50 b of the pumping device50 together with the throttling effect of the bottle-neck region 68, acomparatively high pressure builds up inside the channel portion 66. Thepositive pressure in the channel portion 66 relative to the environmentpreferably ranges from 100 mbar to 500 mbar. This positive pressure issufficient to dispel gas bubbles through the porous membrane 64 from theliquid drawn in, and the gas can then escape through gaps in the housing12. The liquid delivered by the micropump 50 cannot escape through theporous membrane 64 at the aforementioned positive pressure. Thus theliquid entering the bottle-neck region 68 is largely free from gasbubbles. The W-shaped configuration of the channel portion 66, moreparticularly the three curves 66 a, 66 b, 66 c, promote the process ofremoving bubbles, since the bubbles gather at the inside bend in theregion of these curves 66 a, 66 b, 66 c and are further conveyedcomparatively slowly in this region. This gives sufficient time for thegas bubbles to escape through the porous membrane 64. The bottle-neckregion 68 connected directly upstream of the atomizing device 20 leadsto a significant reduction in the pressure of the liquid. The liquidlargely free from gas bubbles therefore flows at a reduced pressure intothe atomizing chamber 22. Since the vibrator 28 has not yet beenactivated at this point, the liquid flows from the inlet side 20 a ofthe atomizing device 20 directly to the outlet side 20 b of theatomizing device 20. The liquid pressure that is reduced by thebottle-neck region 68 to a positive pressure ranging from 0 mbar to 30mbar and preferably from 2 mbar to 10 mbar, is initially not sufficientto force the liquid into the environment by way of the outlet orifices24 a. The outlet orifices 24 a are thus not wetted. Instead, all theliquid delivered flows back into the liquid storage receptacle in thepreparatory phase due to the low flow resistance in the channel portions80, 82. In the preparatory phase, in which only the pumping device 50but not the vibrator 28 is activated, the entire pumped volume of liquidis thus recirculated. Air that may still be present in the atomizingchamber 22 prior to activation of the control switch 18 is either forcedout of the atomizing chamber 22 through the outlet orifices 24 a whenliquid flows into the atomizing chamber or forced through the channelportions 80, 82 into the liquid-containing bladder 30 to be removed fromthe liquid in the debubbling device 60 when the liquid is subsequentlydrawn in.

On termination of the preparatory phase, preferably after approximatelyone second, the vibrator 28 is also activated by the control device 40.As a result, the liquid present in the atomizing chamber 22 is caused tovibrate, which results in a discharge of liquid through the outletorifices 24 a in the form of extremely small droplets. Thus a fineliquid spray is dispensed through the orifice 14 a in the top housingshell 14, and this liquid spray can be inhaled, for example as amedicine, or dispensed onto the skin in the form of a cosmetic deposit,when the appropriate liquid is used.

Once the vibrator 28 has been switched into operation, a portion,preferably half or a major portion of the pumped volume of liquiddelivered by the pumping device 50 to the atomizing device 20 isdispensed through the outlet orifices 24 a. There still remains asignificant portion of the liquid delivered by the pumping device 50,which portion is recirculated to the liquid-containing bladder 30through the channel portions 80, 82. This ensures that any air that mayhave inadvertently entered the atomizing chamber 22 is reliably removedtherefrom. At the same time, the fact that the pumped volumetric flowrate is greater than the discharged volumetric flow rate reliablyensures that a sufficient amount of liquid is present in the atomizingchamber 22 at all times.

The invention claimed is:
 1. An atomizer for atomizing liquids, comprising: a liquid storage receptacle in the form of a dimensionally flexible liquid-containing bladder, an atomizing device having an atomizing chamber that communicates with the ambient atmosphere via a plurality of outlet orifices, the atomizing device having a liquid inlet and a liquid outlet each communicating with the atomizing chamber, and further having a vibrator which vibrates liquid present in the atomizing chamber to atomize same, the atomizing chamber being delimited on one side by the outlet orifices and on an opposite side by a vibrating wall which is vibrated by the vibrator, an intake channel fluidly interconnecting said liquid storage receptacle to the liquid inlet of the atomizing device, a debubbling device located in the intake channel, said debubbling device having a channel portion through which liquid flows on its way to said atomizing chamber and which channel portion is partly delimited by a filter surface, wherein said channel portion: is formed by a groove in a base component of the atomizer, the groove being closed by said filter surface, the filter surface being flat and porous and positioned on said base component, or has at least two straight portions interconnected by at least one curved portion; an electrically actuated pumping device provided in said intake channel for delivering liquid from said liquid storage receptacle to said atomizing chamber, an electronic control device electrically controlling said pumping device and said vibrator, said atomizing device and said pumping device being configured or being controlled by said control device such that during atomization a pumped volumetric flow rate of the liquid transported by said pumping device is greater than a discharged volumetric flow rate through said outlet orifices as achieved by said atomizing device, and a return channel distinct from said intake channel, the return channel fluidly interconnecting the liquid storage receptacle to the liquid outlet of the atomizing device, the return channel draining liquid from said atomizing chamber into said liquid storage receptacle.
 2. The atomizer as defined in claim 1, wherein the pumped volumetric flow rate during atomization is greater than the discharged volumetric flow rate by at least 20%.
 3. The atomizer as defined in claim 1, wherein said control device is adapted to first activate only said pumping device in a preparatory phase prior to commencement of a discharging operation, and second to additionally activate said vibrator on termination of the preparatory phase.
 4. The atomizer as defined in claim 3, wherein said pumping device is configured or is controlled by said control device in such a manner, and said outlet orifices of said atomizing device are constructed in such a manner, that the pressure achieved in the atomizing chamber in the preparatory phase is not sufficient to force liquid through said outlet orifices.
 5. The. atomizer as defined in claim 1, wherein the debubbling device is provided between said pumping device and said atomizing chamber.
 6. The atomizer as defined in claim 1, wherein said pumping device is configured or is controlled by said control device in such a manner, and said debubbling device is configured in such a manner, that the pressure established in said debubbling device suffices to force gas through the filter surface but is not sufficient to force liquid through said filter surface.
 7. The atomizer as defined in claim 1, wherein the liquid present in said liquid storage receptacle contains a pharmaceutically active substance or is a cosmetic product.
 8. An atomizer for atomizing pharmaceutical or cosmetic liquids, said atomizer comprising: a liquid storage receptacle; an atomizing device defining an atomizing chamber, a plurality of outlet orifices in fluid communication with said atomizing chamber and the atmosphere, a liquid inlet and a liquid outlet each in fluid communication with said atomizing chamber, and a vibrating device disposed closely adjacent said atomizing chamber which when actuated vibrates liquid located within said atomizing chamber in order to atomize same; an intake channel disposed to provide fluid communication between said liquid storage receptacle and said liquid inlet of said atomizing device to place said atomizing chamber in fluid communication with said liquid storage receptacle and allow delivery of fluid therein to said atomizing chamber; an electrically-actuated pumping device disposed to deliver liquid from said liquid storage receptacle to said atomizing chamber via said intake channel; an electronic control device electrically controlling and electrically connected to said pumping device and said vibrating device; a return channel separate and distinct from said intake channel, said return channel fluidly interconnecting said liquid storage receptacle to said liquid outlet of said atomizing device to drain liquid from said atomizing chamber and recirculate liquid therein back into said liquid storage receptacle; a housing in which said liquid storage receptacle, said atomizing device, said intake channel, said pumping device, said control device and said return channel are disposed; and a debubbling device disposed between said pumping device and said atomizing chamber in said housing, said debubbling device including a base component and a porous membrane disposed in opposed relation with one another within said housing, said base component defining therein a debubbling groove closed on a side thereof by said membrane, said debubbling groove being in fluid communication with and forming part of said intake channel and having two substantially straight portions and a curved portion disposed between said two substantially straight portions.
 9. The atomizer of claim 8, wherein said atomizing chamber is disposed between said liquid inlet and said liquid outlet.
 10. The atomizer of claim 8, wherein said atomizing device includes a perforated plate defining therein said outlet orifices and a vibrating wall disposed in juxtaposed and facing relation with said perforated plate, said vibrating device being attached to said vibrating wall and vibrating same when actuated by said control device.
 11. The atomizer of claim 8, wherein said control device electrically actuates only said pumping device in a preparatory phase prior to commencement of a discharging operation of said atomizer, said atomizer in the preparatory phase being configured to deliver liquid from said liquid storage receptacle to said atomizing chamber via said intake channel and then to recirculate the liquid to said liquid storage receptacle via said return channel, said pumping device achieving a pressure in said atomizing chamber in the preparatory phase which is insufficient to force liquid through said outlet orifices.
 12. The atomizer of claim 11, wherein said control device electrically actuates both said pumping device and said vibrating device upon termination of the preparatory phase to commence the discharging operation, said atomizer during the discharging operation dispensing liquid through said outlet orifices, wherein a pumped volumetric flow rate of liquid transported by said pumping device during the discharging operation is greater than a discharged volumetric flow rate of liquid dispensed through said outlet orifices. 